4-hydroxy-3,5-dimethoxybenzaldehyde

Toxicity to aquatic algae and cyanobacteria

Administrative data

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

test procedure in accordance with generally accepted scientific standards and described in sufficient detail

Data source

Reference

Reference Type:

publication

Title:

Unnamed

Year:

1998

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

- Principle of test:
- Short description of test conditions:
- Parameters analysed / observed:

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

4-hydroxy-3,5-dimethoxybenzaldehyde

EC Number:

205-167-5

EC Name:

4-hydroxy-3,5-dimethoxybenzaldehyde

Cas Number:

134-96-3

Molecular formula:

C9H10O4

IUPAC Name:

4-hydroxy-3,5-dimethoxybenzaldehyde

Test material form:

not specified

Details on test material:

Solved in Ethanol. Source: Sigma Chemical Co.

Sampling and analysis

Analytical monitoring:

not specified

Test solutions

Details on test solutions:

Compound purity was compensated for when preparing stock solutions. Test solutions were prepared in tenfold concentration increments, and four replications were used for each concentration and control.

Test organisms

Test organisms (species):

Oscillatoria sp.

Details on test organisms:

Oscillatoria cf. chalybea, isolated from a west-central Mississippi cattish production pond (van der Ploeg et al. 1995)

Unialgal cultures were grown and maintained in continuous, steady-states at 29°C under continuous light by the method of van der Ploeg et al. (1995) except that light intensity was 18-29 μE/m /sec and air flow rate was 16-33 L/hr. Cell density in the continuous cultures was maintained at 0.18-0.27 A (absorbance) for O. cf. chalybea, 0.19-0.26 A for S. capricornutum, 0.28-0.33 A for Anabaena sp. LP 691, and 0.20-0.24 A for P. simplex. Cell density was measured at 750 nm using a Gilford model Response UV-VIS spectrophotometer (Gilford Instrument Laboratories, Inc., Oberlin, OH).

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

5 d

Test conditions

Test temperature:

25-27°C

Nominal and measured concentrations:

1, 10, 100 and 1000 μM

Details on test conditions:

A rapid microtiter plate-based assay developed previously for screening compounds for selectivity as cyanobacterial algicides was used (Schrader et al. 1997).

Microplates were placed in a growth chamber at 25-27°C and illuminated by three overhead fluorescent lamps (40 W, cool white) at a light intensity of 20-28
2 μE/m /sec. Optical densities of each well were measured daily for 5 d at 650 nm using a Packard model Spectracount microplate photometer (Packard Instrument Company, Meriden, CT).

Results and discussion

Effect concentrations

Key result

Duration:

5 d

Dose descriptor:

LOEC

Effect conc.:

100 µmol/L

Nominal / measured:

nominal

Basis for effect:

growth rate

Applicant's summary and conclusion

Conclusions:

The LOEC for Oscillatoria cf. chalybea growth was 100 μM.